According to The Associated Press, Heritage Auctions sold the three comic strips to three collectors, who wished to remain anonymous. The Dallas auction house had expected the pieces to bring in more than $30,000 combined (the June 5 strip alone went for $35,840).

The artwork was displayed last month at Comic-Con International before it went up for auction. At Watterson’s request, the strips were sold on behalf of Team Cul de Sac, the charity founded by Chris Sparks to honor Cul de Sac creator Richard Thompson, who has Parkinson’s disease.